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Kolossus | Big Dog Carrier & Backpacking Pack


Completely redesigned in appearance, construction, and functionality, the Kolossus, formerly known as the Rover 2, is THE big dog backpack carrier that now doubles as a backpacking pack. It is ideal for carrying medium to large dogs and available in sizes L-XXL. Kolossus technology is top of the line in pet/human safety and comfort. Adjustable shoulder/torso sizing makes this backpack more suitable than ever for all body types (as long as you can withstand the weight). When you’re not carrying your 4-legged friend, the backpack easily converts to carry your gear with up to 60 liters of space. Use this backpack for strenuous hikes, bike rides, and public transit.

For Dogs Ranging 20-80 lbs (9-36 kgs)
50-60 liter capacity

Kolossus sizing length from the collar to the base of the tail: L 20-23 inches, XL 23-26 inches, XXL 26-29 inches

View More Sizing Instruction

  • Backpacking Pack Conversion
  • Adjustable Shoulder/Torso Height
  • Removable Lap Belt with Hip Pockets & Waste Bag Dispenser
  • Internal Frame with Inner Padding for Dog Comfort
  • Padded Back Panel with Increased Airflow
  • Removable Storage/Dog Back Support Pack with Hydro Port
  • Weight Distribution Straps
  • Side Cooling Venting Zippers
  • Wide Base to accommodate your pet and its tail
  • Detachable Dog Sun/Rain Hood
  • Dog Lumbar Support Straps
  • 300D Ripstop Oxford Polyester Material
  • Matching Hook & Loop Strip for Custom Patch

Compare K9 Sport Sack Carriers

Rover 2  Comparison

View Patent Info


All K9 Sport Sack carriers are specially developed under the close direction of animal professionals, veterinarians, dog trainers, and outdoor product engineers to be ergonomic, safe, and strong.

Customer Reviews

Based on 63 reviews
Fay Berry

This pack is so handy! Whether my dog is tired (not too often LOL), the terrain is too rough, or we’re simply wanting to socialize out in the public without exposing him to the ground, etc. he gladly fits into the bag and he’s happy to be in it! It works, it’s comfortable for us BOTH and EASY to use. Did I mention the colors and extra pockets? The ability to customize with Velcro patches? Yes, please!

Awesome carrier!

We are now able to take our aging basset on walks and hikes. Great backpack!

Jennifer Leonard
High quality!

Very thoughtful design, my only challenge was one of my dogs is unable to do a sit command to get him low enough to slide inside, wish there was a Plan B, LOL. Other than that, I highly recommend as a fun way to keep your dog included in all activities! 5 stars!

Michael Daugherty
Great Carrier for Larger Dogs on Motorcycles

Bought this because I felt guilty leaving my 50lb australian shepherd at home when I went out motorcycle riding, which is almost every day in the summer. Wasn't sure if it was gonna work or not but it turns out to be a great pack!

Could use some improvements on the buckles and strap hardware (metal instead of plastic) but I'm also using it pretty strenuously. Have nearly 1000 miles of riding with my dog Beau in this, very satisfied. Would strongly recommend!


We were heading to Acadia National Park and wanted to see as much as we could but with Riley being 15 years old and having a leg injury we figured we needed to come up with something to carry her when she needed a break from walking. Saw the Kolossus and immediately ordered it. I added the water repelling treatment and the name tag and the order was complete. Then our departure date was moved up and we needed the pack sooner. I called up customer service, they fast tracked the order and we got the pack before we left and we did some extra sight seeing with Riley because we had the pack. She is still getting use to it as she has always been a high energy Wheaty(think they all are). Need to get her higher up in the pack and we will continue to practice with her in it.
Customer service really stepped up to get us the pack so big shout out to them! Highly recommend these products.